热轧带钢层流冷却中的温度演变及返红规律

用有限元法模拟热轧带钢层流冷却中的温度场并计算典型位置处的冷却速度.分析水冷期间和随后返红过程冷却速度周期性变化规律,发现在轧件横断面厚度方向上距离表面大约半厚度的1/3处存在一条冷却速度临界线;在临界线与表面之间冷却速度有正负交替现象;此临界线是冷却过程中瞬时内部热输出区与热输入区(返红区域)的分界线;在返红区域回归出返红温度随经历时间和各点到表面距离的变化规律的关系模型.此研究为组织性能预测和控制提供了参考数据.

Temperature Evolution and Re-Reddening Behavior of Hot Rolled Strip During Laminar Cooling

Analyzes the temperature field of hot rolled strip during laminar cooling by finite element method,and calculates the cooling rate at typical positions to investigate how the cooling rate variea periodically during water cooling and subsequent re-reddening.It is found that there is a critical line of cooling rate at the position that is sectionally 1/3 half-thickness away from the strip surface,and the cooling rate varies alternately between positive and negative values between the surface and the critical line.It implies that the critical line is in fact a demarcation line between the transient heat output zone and input zone(re-reddening zone) in cooling process.A regression model for the relationship among re-reddening temperature,time and distances from different node points to the surface is thus obtained in re-reddening zone.The results can be used as reference for the prediction and control of microstructures and properties of strips in rolling process.